Plasma apparatus using a valve

ABSTRACT

Provided is a plasma apparatus using a valve, which comprises a discharge device with an electrode exposed to the combustion chamber installed in a cylinder head, an antenna installed on the valve face of a valve head, an electromagnetic wave transmission line installed in a valve stem with one end connected to the antenna and the other end covered with an insulator or dielectric and extending to a power-receiving portion positioned at a location fitting into the guide hole in the valve stem, and an electromagnetic wave generator for feeding an electromagnetic waves to the power-receiving portion. At the compression stroke when the combustion chamber side opening of an intake port or an exhaust port is closed with the valve head, discharge is generated with the electrode of the discharge device and the electromagnetic waves fed from the electromagnetic wave generator through the electromagnetic wave transmission line are radiated from the antenna.

TECHNICAL FIELD

The present invention belongs to the field of the internal combustionengine and relates to the improvement of combustion in the combustionchamber of an internal combustion engine in which a combustion chamberside opening of an intake port or an exhaust port is opened and closedat a given timing with an intake valve or an exhaust valve.

BACKGROUND OF THE INVENTION

Patent Document 1 shows an internal combustion engine including acombustion/reaction chamber, auto-ignition means, microwave radiationmeans, and control means. The combustion/reaction chamber consists of acylinder and piston. The combustion/reaction chamber is supplied with amixture of reactive and oxidation gas. In the combustion/reactionchamber, a plasma reaction of the mixture is carried out. Theauto-ignition means automatically ignites the mixture by injecting amixture of reactive and oxidation gas under high pressure, compressingthe mixture and increasing the temperature. The microwave radiationmeans radiates the combustion/reaction chamber with microwaves. Thecontrol means controls the auto-ignition means and microwave radiationmeans, and repeats a cycle that involves radiating thecombustion/reaction chamber with microwaves so that large amounts ofhydroxyl (OH) radicals and ozone (O₃) are generated from the moisture inthe combustion/reaction chamber mixture, which then oxidizes and reactschemically, combustion of the mixture in the combustion/reaction chamberis promoted by the large amount of OH radicals and O₃, when theauto-ignition, means ignites the mixture.

The internal-combustion engine with an electrical field formed in thecombustion chamber is disclosed in Patent Documents 2 to 4. PatentDocument 2 outlines an internal combustion engine, containing thefollowing: a cylinder block with a cylinder wall; a cylinder head on thecylinder block; a piston in the cylinder block; a combustion chamberformed by the cylinder wall, cylinder head and piston; and an electricalfield apply means for applying an electrical field in the combustionchamber during combustion of the engine. When an electrical field isapplied to the flame in this internal combustion engine, ions move intothe flame and collide. This increases the flame propagation speed, andthe ions in the gas that has already burnt move to unburned gas andalter the chemical reaction in the unburned gas. This maintains auniform flame temperature and controls engine knock.

-   [Patent Document 1] Japanese Patent Application Laid-open    Publication No. 2007-113570-   [Patent Document 2] Japanese Patent Application Laid-open    Publication No. 2000-179412-   [Patent Document 3] Japanese Patent Application Laid-open    Publication No. 2002-295259-   [Patent Document 4] Japanese Patent Application Laid-open    Publication No. 2002-295264

SUMMARY OF THE INVENTION

The inventor of the present invention extrapolated the mechanism ofcombustion promotion in the internal combustion engine which isdisclosed in Patent Document 1, and obtained a constant finding aboutthe mechanism. In this mechanism, a small amount of plasma is dischargedfirstly. The plasma is irradiated with microwaves for a given period oftime, so that the amount of plasma increases. Thus a large amount of OHradicals and ozone is generated from moisture in the air-fuel mixturewithin a short period of time, promoting an air-fuel mixture reaction.This mechanism of the combustion promotion, obtained by generating alarge amount of OH radicals and ozone, promotes combustion with plasma,is entirely different from combustion-promoting mechanisms that use ionsto increase flame propagation speed, disclosed in Patent Documents 2through 4.

In the art of Patent Documents 2, said electrical field apply meanscomprises a conductive member arranged so as to apply the electricalfield in the combustion chamber. This conductive member is anickel-chromium alloy wire, with a preferable diameter of 1.0 mm, andinstalled in an annular groove established in an annular insulatorinserted in the cylinder wall of the cylinder block. In the art ofPatent Documents 2 through 4, the substantial modifications required forthe cylinder block and other structural components of a conventionalinternal combustion engine. These modifications increase the timerequired to design an engine, and do not permit the sharing of partswith existing internal combustion engines.

In the view of the foregoing, the present invention has been achieved.An object of the invention is to provide a plasma apparatus using avalve, which can easily realize the combustion-promoting mechanism,obtained by generating a large amount of OH radicals and ozone withplasma, by using the existing internal combustion engine as far aspossible. By this realization, it can be realized to minimize the timerequired to design an engine and facilitate the sharing of many partsbetween existing internal combustion engines.

The present invention is plasma apparatus using a valve, which isinstalled in an internal combustion engine in which the combustionchamber side opening of a intake port or an exhaust port is opened andclosed at a given timing with a valve head at the end of a valve stem ofa intake valve or an exhaust valve, the intake port or the exhaust portis formed in a cylinder head and connects to the combustion chamber tobe part of the exhaust passage, the valve stem fits into a guide holepenetrating from the intake port or the exhaust port to the outer wallof the cylinder head and reciprocating freely, the plasma apparatususing a valve comprises, a discharge device with an electrode exposed tothe combustion chamber installed in the cylinder head, an antennainstalled on the valve face of the valve head, an electromagnetic wavetransmission line installed in the valve stem with one end connected tothe antenna and the other end, covered with an insulator or dielectricand extending to a power-receiving portion, which is positioned at alocation fitting into the guide hole or at a location farther from thevalve head in the valve stem, and an electromagnetic wave generator forfeeding electromagnetic waves to the power-receiving portion, whereinthe plasma apparatus is configured such that discharge is generated withthe electrode of the discharge device and the electromagnetic waves fedfrom the electromagnetic wave generator through the electromagnetic wavetransmission line are radiated from the antenna at the compressionstroke when the combustion chamber side opening of the intake port orthe exhaust port is closed with the valve head.

At the compression stroke in the actuation of the internal combustionengine, discharge is generated at the electrode of the discharge deviceand the electromagnetic waves fed from the electromagnetic wavegenerator through the electromagnetic wave transmission line areradiated from the antenna. Therefore, the plasma is generated near theelectrode. This plasma receives energy of an electromagnetic waves(electromagnetic wave pulse) supplied from the antenna for a givenperiod of time. As a result, the plasma generates a large amount of OHradicals and ozone to promote the combustion. In fact electrons near theelectrode are accelerated, fly out of the plasma area, and collide withgas such as air or the air-fuel mixture in surrounding area of saidplasma. The gas in the surrounding area is ionized by these collisionsand becomes plasma. Electrons also exist in the newly formed plasma.These also are accelerated by the electromagnetic wave pulse and collidewith surrounding gas. The gas ionizes like an avalanche and floatingelectrons are produced in the surrounding area by chains of theseelectron acceleration and collision with electron and gas inside plasma.These phenomena spread to the area around discharge plasma in sequence,then the surrounding area get into plasma state. In the result of thephenomena as mentioned above it, the volume of plasma increases. Thenthe electrons recombine rather than dissociate at the time when theelectromagnetic wave pulse radiation is stopped. As a result, theelectron density decreases, and the volume of plasma decreases as well.The plasma disappears when the electron recombination is completed. Alarge amount of OH radicals and ozone is generated from moisture in thegas mixture as a result of a large amount of the generated plasma,promoting the combustion of the mixture.

In this case, the cylinder block etc. which are the major structuralmaterials can be used without modification compared with existinginternal combustion engine. And the intake valve, exhaust valve, and thestructure around these valves are remodeled. With the exception ofinternal combustion engine which basically needs spark plug, it maymount a discharge device on the cylinder head in internal combustionengine that is not necessary a spark plug. Therefore, it is realized tominimize the time required to design an internal combustion engine andshare many parts with existing internal combustion engines.

The plasma apparatus using a valve of the present invention may beapplicable for which the antenna forms nearly a C shape to surround thecenter on the valve face and one end of the antenna is connected to theelectromagnetic wave transmission line.

This makes the antenna compact on the back face.

The plasma apparatus of the present invention may be applicable forwhich the power-receiving portion exposed on the outer wall of valvestem, and the plasma apparatus includes, a dielectric member installedin the cylinder head and near the power-receiving portion, at least whenthe valve head closes the combustion chamber side opening of the intakeport or the exhaust port, made from dielectric material, and apower-feeding member made from conductive material, which is installedin the cylinder head close to the dielectric member opposite the valvestem, wherein plasma apparatus is configured such that the power-feedingmember would be fed the electromagnetic waves from the electromagneticwave generator.

This makes it possible to have non-contact electromagnetic wavetransmission from the electromagnetic wave generator to theelectromagnetic wave transmission line through the power-feeding member,the dielectric member, and the power-receiving portion.

The plasma apparatus of the present invention may be applicable forwhich a valve guide mounted hole, which penetrates from the intake portor the exhaust port to the outer wall of cylinder head, is installed inthe cylinder head, a valve guide with trunk shape made from dielectricmaterial fits into the valve guide mounted hole allowing a hole in thevalve guide to serve as a guide hole, and a portion of the valve guide,approaching the power-receiving portion at least when the valve headcloses the combustion chamber side opening of the intake port or theexhaust port, is the dielectric member.

This makes it possible to have non-contact electromagnetic wavetransmission from the electromagnetic wave generator to theelectromagnetic wave transmission line by using heretofore knownmechanism for mounting the valve guide.

The plasma apparatus using a valve of the present invention may beapplicable for which the electrode is located close to a portion wherethe electric field intensity generated by the electromagnetic wavesaround the valve face of the valve head becomes strong when theelectromagnetic waves are fed to the antenna.

This makes it possible that the electromagnetic wave pulse irradiatesthe plasma generated by the discharge at the electrode from the antennanear plasma. The energy is intensively supplied to said plasma. As aresult, a large amount of OH radicals and ozone is efficientlygenerated, further promoting the combustion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a vertical cross-sectional view of combustion chamber in aninternal combustion engine with the plasma apparatus using a valve inthe first embodiment of the present invention;

FIG. 2 shows an enlarged vertical cross-sectional view of exhaust portin an internal combustion engine with the plasma apparatus using a valvein the first embodiment of the present invention;

FIG. 3 shows an enlarged vertical cross-sectional view of exhaust valveused in the plasma apparatus using a valve in the first embodiment ofthe present invention;

FIG. 4 shows an enlarged view of exhaust valve used in the plasmaapparatus using a valve in the first embodiment of the presentinvention, as seen from the valve face; and

FIG. 5 shows an enlarged vertical cross-sectional view of exhaust valveused in the plasma apparatus using a valve in the second embodiment ofthe present invention.

DESCRIPTION OF REFERENCE CHARACTERS

E Internal combustion engine

100 Cylinder block

110 Cylinder

200 Piston

300 Cylinder head

310 Intake port

311 Opening

330 Guide hole

320 Exhaust port

321 Opening

340 Guide hole

350 Valve guide mounted hole

360 Valve guide

400 Combustion chamber

510 Intake valve

511 Valve stem

512 Valve head

520 Exhaust valve

521 Valve stem

521 a Basic portion

521 b Periphery portion

522 Valve head

522 a Basic portion

522 b Valve face

810 Discharge device

812 First electrode

813 Second electrode

820 Antenna

830 Electromagnetic wave transmission line

840 Electromagnetic wave generator

850 Dielectric member

860 Power-feeding member

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described.FIG. 1 shows the embodiments of the internal combustion engine Ecomprising the plasma apparatus using a valve of the present invention.The present invention targets reciprocating engines. In this embodiment,engine E is a four-cycle gasoline engine. Cylinder block 100 containscylinder 110, which has an approximately circular cross section.Cylinder 110 penetrates cylinder block 100. Piston 200, which has anapproximately circular cross section corresponding to cylinder 110, fitsinto cylinder 110 and reciprocates freely. Cylinder head 300 isassembled on the anti-crankcase side of cylinder block 110. Cylinderhead 300, piston 200, and cylinder 110 form combustion chamber 400. Item910 is a connecting rod, with one end connected to piston 200 and theother end connected to crankshaft 920, which is the output shaft.Cylinder head 300 has intake port 310, which is a component of theintake line, and exhaust port 320, which is a component of the exhaustline. One end of intake port 310 connects to combustion chamber 400; theother end is open at the outside wall of cylinder head 300. One end ofexhaust port 320 connects to combustion chamber 400; the other end isopen at the outside wall of cylinder head 300. The cylinder head hasguide hole 330 that passes through intake port 310 to the outside wallof cylinder head 300. Rod-shaped valve stem 511 of intake valve 510 fitsinto guiding hole 330 and reciprocates freely. Umbrella-shaped valvehead 512, set at the end of valve stem 511, opens and closes thecombustion chamber side opening of intake port 310 at a given timing bya valve open/close mechanism having a cam and so on (not shown in thefigure). Cylinder head 300 has guiding hole 340 that passes throughexhaust port 320 to the outside wall of cylinder head 300. Rod-shapedvalve stem 521 of exhaust valve 520 fits into guiding hole 340 andreciprocates freely. Umbrella-shaped valve head 522, set at the end ofvalve stem 521, opens and closes the combustion chamber side opening 321of the exhaust port 320 at a given time by the valve open/closemechanism having cam and so on (not shown in the figure). Item 810 is aspark plug installed in cylinder head 300 to expose a pair of electrodes812, 813 to combustion chamber 400. Spark plug 810 discharges at theelectrodes when piston 200 is near top dead center. Therefore, fourstrokes (intake, compression, combustion of mixture, and exhaust ofexhaust gas) occur while piston 200 reciprocates between top dead centerand bottom dead center twice. However, this embodiment does not restrictthe interpretation of the internal combustion engine targeted by thepresent invention. The present invention is also suitable for use withtwo-stroke internal combustion engines and diesel engines. Targetgasoline engines include direct-injection gasoline engines, which createa mixture inside the combustion chamber to inject fuel into the intakeair. Target diesel engines include direct-injection diesel engines,which inject fuel into the combustion chamber directly, anddivided-chamber diesel engines, which inject fuel into the dividedchamber. Internal combustion engine E in this embodiment has fourcylinders, but this does not restrict number of cylinders of theinternal combustion engine targeted by the present invention. Theinternal combustion engine for this embodiment has two intake valves 510and two exhaust valves 520, but this does not restrict the number ofintake or exhaust valves of the internal combustion engine targeted bythe present invention. Item 700 is a gasket installed between cylinderblock 100 and cylinder head 300.

Said spark plug 810 also functions as a discharge device 810 of theplasma apparatus using a valve of the present invention. This dischargedevice 810 is installed in the cylinder head 300. This discharge device810 is set on the wall of the combustion chamber 400. This dischargedevice 810 comprises a connection 811 set outside of the combustionchamber 400, a first electrode 812 electrically-connected to theconnection 811, and a second electrode 813 contacts the cylinder head300 and connects in ground. The first electrode 812 and the secondelectrode 813 are placed opposite at specified interval on the dischargedevice 810. Both of them are exposed to the combustion chamber 400. Thedischarge device 810 is connected to a discharge voltage generator 950which generates voltage for discharge. Here, the discharge voltagegenerator 950 is DC 12V power supply and a spark coil. The cylinder head300 is earthed and the connection 811 connects to the discharge voltagegenerator 950. In case of applying voltage between the cylinder head 300and the connection 811, discharge happens between the first electrode812 and the second electrode 813. As described above, it may dischargebetween electrode of the discharge device and a wall of the combustionchamber, or other earthed members without a pair of electrodes. Forexample, in case that the internal combustion engine is a diesel engine,it does not install a spark plug under normal circumstances. Thereforeit needs to install the discharge device, having an electrode exposed tothe combustion chamber, on the cylinder head. In this case, it mayinstall the spark plug as explained above as the discharge device, andconnects it to the discharge voltage generator. However the dischargedevice does not always need to use a spark plug, because the dischargedevice requires generating plasma by discharge regardless the size. Thedischarge device may be used for example piezo element or other device.

An antenna 820 is installed on the valve face 522 b of the valve head522 of said exhaust valve 520 as shown in FIG. 2 and FIG. 4. The valveface 522 b is a surface on opposite side against a back-face faces tothe exhaust port 320 of the valve head 522. The valve face 522 b facesthe combustion chamber 400 when the combustion chamber opening 321 ofthe exhaust port 320 is closed with the valve head 522. The antenna 820is made from metal. However, it can be made from a conductor, dielectricor insulator, provided that electromagnetic waves are radiated well fromit to the combustion chamber when they are supplied between the antennaand the earth member. The Antenna 820 is a bar-style unit with curvatureand forms nearly a C shape to surround the center of the valve face 522b of the valve head 522. The antenna 820 radiates electromagnetic wavesto the combustion chamber 400. In fact, the antenna 820 forms nearly a Cshape, in sum circularity with hiatus, to surround valve face 522 b, asseen along the direction of valve stem 521 extending. The inside of aportion of the valve stem 521 fitting into a guide hole 340 is made fromdielectric and becomes a basic portion 521 a. A periphery side portionof this basic portion 521 a, the portion fits into the guide hole 340,is made from metal and becomes a periphery portion 521 b. A reason forthe periphery portion 521 b made from metal is to enhance rub resistanceand burning resistance, and it can be made from other materials. Also,no fitting portions into the guide hole 340 can be made from dielectricon the valve stem 521. In addition, a successive portion to the basicportion 521 a of said valve stem 521 is made from dielectric and becomesa basic portion 522 a in the valve head 522. And a valve face 522 b onthe combustion chamber side of the valve head 522 is made from metal. Areason for the valve face 522 b made from metal is to enhance burningresistance. However, it can be made from other materials. The antenna820 is installed on the back of the basic portion 522 a in the valvehead 522. In this case, ceramic is used as dielectric. However, otherdielectrics or insults can be used. For example, the length of theantenna 820 is set to a quarter of wavelength in electromagnetic waves,standing wave is generated in the antenna 820. Thus, electrical fieldstrength at the end of antenna 820 becomes strong. For example, thelength of the antenna 820 is set to a multiple of a quarter wavelengthsof the electromagnetic waves so that standing waves are generated in theantenna 820, increasing the electrical field at multiple points, wherethe anti-nodes of the standing waves are generated, in the antenna 820.The antenna 820 can be buried in the valve head 522. In addition, thefirst electrode 821 and the second electrode 813 are located close to aportion that electric field intensity, generated by the electromagneticwaves around the valve face 522 b of the valve head 522, becomes strongwhen the electromagnetic waves are fed to said antenna 820. In thiscase, the top of the antenna 820 gets close to the first current 812 andthe second current 813. Therefore, upon supplying electromagnetic wavesbetween the antenna 820 and the cylinder head 300, which is an earthmember, the electromagnetic waves is radiated from the antenna 820 tothe combustion chamber 400. And, one end of the antenna 820 connects tothe electromagnetic wave transmission line 830, which is explained inbelow. In this embodiment, antenna 820 is a rod-shaped monopole antennathat is curved one. However, this does not restrict the type of antennain the plasma apparatus of the present invention. Therefore, antenna ofthe plasma apparatus of the present invention may be dipole antenna,Yagi-Uda antenna, a single feed antenna, a loop antenna, a phasedifference feed antenna, a ground-plane antenna, a anti-ground-planetype vertical antenna, a beam antenna, a horizontally polarizedomni-directional antenna, a corner antenna, comb antenna, or one of theother linear antenna, a micro-strip antenna, a inverted-F antenna, orother plane antenna, slotted array antenna, a parabolic antenna, a hornantenna, a horn reflector antenna, a cassegrain antenna or other solidantennas, Beverage antenna or other progressive wave antennas, star typeEH antennas, bridge type EH antennas or other EH antennas, a barantenna, a minute loop antennas or one of the other magnetic fieldantennas or dielectric substance antennas.

Electromagnetic wave transmission line 830, made from copper line, isinstalled in valve stem 521 of exhaust valve 520, as shown in FIG. 3.This electromagnetic waves transmission line 780 is made from copperline. Electromagnetic wave transmission line 830 may also be made fromany conductor, insulator, or dielectric, as long as electromagneticwaves are transmitted well to antenna 820 when they are supplied betweenantenna 820 and the earthed member. A possible variation is anelectromagnetic wave transmission line that consists of a waveguide madefrom a conductor or dielectric. Power-receiving portion 521 c isinstalled in a fitting portion into valve guide 340 of valve stem 521.Power-receiving portion 521 c can be made from a conductor, dielectric,or insulator. Here, power-receiving portion 521 c is located at theperiphery of valve stem 521, but it can also be located inside it. Theconfiguration and material of power-receiving portion 521 c is selectedaccording to the connection method to power-feeding member 860, asdescribed below. Power-receiving portion 521 c can be positioned at alocation farther from the valve head in the valve head than a fittingportion into the guide hole of the valve stem. One end ofelectromagnetic wave transmission line 830 is connected to antenna 820.The other end, which is covered with an insulator or dielectric, extendsto power-receiving portion 521 c at a fitting portion into the guidehole 340 of valve stem 521 and connects to it. Electromagnetic wavetransmission line 830 runs inside basic portion 521 a of valve stem 521.Therefore the other end of electromagnetic wave transmission line 830 iscovered with a dielectric and extends to power-receiving portion 521 c.Whereas basic portion 521 a is made from dielectric, the other end ofthe electromagnetic wave transmission line is covered with an insulatorand extends to power-receiving portion. Thus, when electromagnetic wavesare supplied between power-receiving portion 521 c and the earth membersuch as cylinder head 300, they are introduced into antenna 820.

Electromagnetic wave generator 840, which supplies electromagnetic wavesto power-receiving portion 521 c, is installed in internal combustionengine E or its surroundings. Electromagnetic wave generator 840generates electromagnetic waves. In this embodiment of electromagneticwave generator 840 is a magnetron that generates 2.4-GHz-bandwidthmicrowaves. However, this does not restrict interpretation ofcomposition of electromagnetic wave generator of the plasma apparatus ofthe present invention.

Power-receiving portion 521 c is exposed on the outer surface of valvestem 521 in exhaust valve 520, as shown in FIGS. 2 and 3. Dielectricmember 850 and power-feeding member 860 are in Cylinder head 300.Dielectric member 850 is made from a ceramic and approachespower-receiving portion 521 c at least when valve head 522 of exhaustvalve 520 closes the exhaust port opening 321 in the side of thecombustion chamber. Dielectric member 850 must be made from adielectric. Power-feeding member 860 is made from metal. Power-feedingmember 860 is close to the dielectric member 850 opposite the valve stemof exhaust valve 520. Power-feeding member 860 must be made fromconductive material. The electromagnetic wave transmission methodbetween power-feeding member 860 and power-receiving portion 521 c viadielectric member 850 can be either electric coupling (capacitive) ormagnetic coupling (dielectric). The configuration and material ofpower-feeding member 860 and power-receiving portion 521 c may beselected according to the method. For example, in the case of electriccoupling, power-feeding member 860 and power-receiving portion 521 cshould be conductive plates facing each other. The power feeding member860 and the power receiving portion 521 c may be respectively electricantenna with predefined advantage to electromagnetic waves generated bythe electromagnetic wave generator 840. In the case of magneticcoupling, power-feeding member 860 and power-receiving portion 521 cshould be conductive coils. The power feeding member 860 and the powerreceiving portion 521 c may be respectively a magnetic antenna withpredefined advantage to electromagnetic waves generated by theelectromagnetic wave generator 840. As a result, the electromagneticwave generator 840 provides the power feeding member 860 withelectromagnetic waves when the power feeding member 860 receives anoutput signal of the electromagnetic wave generator 840.

As shown in FIG. 2, valve guide mounted hole 350, which penetrates fromthe exhaust port 320 to the outer wall of cylinder head 300, isinstalled in the cylinder head 300. Valve guide with trunk shape madefrom a ceramics fits into the valve guide mounted hole 350, allowing ahole in the valve guide 360 to serve as a guide hole 340. Valve guidemay be made from dielectric material. In valve guide 360, a portionapproaching the power-receiving portion 521 c at least when the valvehead 522 of the exhaust valve 520 closes the combustion chamber sideopening of the exhaust port 320 is the dielectric member 850.

And at the compression stroke when said valve head 522 closes thecombustion chamber side opening 321 of said exhaust port 320, adischarge is generated between first electrode 812 and second electrode813, and electromagnetic waves fed from the electromagnetic wavegenerator 840 through the electromagnetic wave transmission line 830 areradiated from the antenna 820. Cylinder block 100 or cylinder head 300are earthed. The earth terminals of discharge voltage generator 950 andelectromagnetic wave generator 840 are earthed. Discharge voltagegenerator 950 and electromagnetic wave generator 840 are controlled bycontroller 880, which has a CPU, memory, and storage etc, and outputscontrol signals after computing input signals. Crank angle detectionsignals are sent from crank angle detector 890 to controller 880.Therefore, controller 880 receives signals from crank angle detector 890and controls the actuations of discharge device 810 and electromagneticwave generator 840. However, this does not restrict the control methodand the composition of the input-output signals as for the plasmaapparatus of the present invention.

At the compression stroke in the actuation of the internal combustionengine E, discharge is generated at the first electrode 812 and thesecond electrode 813 of the discharge device 810 and the electromagneticwaves fed from the electromagnetic wave generator 840 through theelectromagnetic wave transmission line 830 are radiated from the antenna820. Therefore, the plasma is generated near the first electrode 812 andsecond electrode 813. This plasma receives energy of an electromagneticwaves (electromagnetic wave pulse) supplied from the antenna 820 for agiven period of time. As a result, the plasma generates a large amountof OH radicals and ozone to promote the combustion. In fact electronsnear the first electrode 812 and the second electrode 813 areaccelerated, fly out of the plasma area, and collide with gas such asair or the air-fuel mixture in surrounding area of said plasma. The gasin the surrounding area is ionized by these collisions and becomesplasma. Electrons also exist in the newly formed plasma. These also areaccelerated by the electromagnetic wave pulse and collide withsurrounding gas. The gas ionizes like an avalanche and floatingelectrons are produced in the surrounding area by chains of theseelectron acceleration and collision with electron and gas inside plasma.These phenomena spread to the area around discharge plasma in sequence,then the surrounding area get into plasma state. In the result of thephenomena as mentioned above it, the volume of plasma increases. Thenthe electrons recombine rather than dissociate at the time when theelectromagnetic wave pulse radiation is stopped. As a result, theelectron density decreases, and the volume of plasma decreases as well.The plasma disappears when the electron recombination is completed. Alarge amount of OH radicals and ozone is generated from moisture in thegas mixture as a result of a large amount of the generated plasma,promoting the combustion of the mixture.

In this case, the cylinder block 100 etc. which are the major structuralmaterials can be used without modification compared with existinginternal combustion engine. Additionally, the exhaust valve 520, and thestructure around this valve are remodeled. With the exception ofinternal combustion engine E which basically needs spark plug 810, itmay mount a discharge device on the cylinder head in internal combustionengine E that is not necessary a spark plug 810. Therefore, it isrealized to minimize the time required to design an internal combustionengine E and share many parts with existing internal combustion engines.

The configuration and structure of the antenna are not restricted forthe plasma apparatus using a valve of the present invention. Even thoughthere are various embodiments, said antenna 820 forms nearly a C shapeto surround the center of the valve face 522 b of the valve head 522 asfor the plasma apparatus in the first embodiment. One end of antenna 820is connected to electromagnetic wave transmission line 830. This makesthe antenna 820 compact on the valve face 522 b.

The structure for transmitting electromagnetic waves from theelectromagnetic wave generator to the electromagnetic wave transmissionline is not restricted for the plasma apparatus using a valve of thepresent invention. In the first embodiment of the plasma apparatus,power-receiving portion 521 c is exposed on the outer surface of valvestem 521 of exhaust valve 520 among such varied embodiments. The plasmaapparatus has dielectric member 850 and power-feeding member 860.Dielectric member 850 is installed in cylinder head 300 and approachespower-receiving portion 521 c at least when valve head 522 of exhaustvalve 520 closes the exhaust port 320 opening in the side of combustionchamber. Dielectric member 850 is made from dielectric material.Power-feeding member 860 is installed in cylinder head 300.Power-feeding member 860 is close to the dielectric member 850 oppositethe valve stem 521. Power-feeding member 860 is made from conductivematerial. Power-feeding member 860 is fed electromagnetic waves fromelectromagnetic wave generator 840. This makes it possible to havenon-contact electromagnetic wave transmission from electromagnetic wavegenerator 840 to electromagnetic wave transmission line 830 throughpower-feeding member 860, dielectric member 850, and power-receivingportion 521 c.

The structure near the guide hole is not restricted for the plasmaapparatus using a valve of the present invention. In the firstembodiment of the plasma apparatus, a valve guide mounted hole 350,which penetrates from the exhaust port 320 to the outer wall of cylinderhead 300, is installed in the cylinder head 300 among such variedembodiments. A valve guide 360 with trunk shape, made from dielectricmaterial, fits into the valve guide mounted hole 350 allowing a hole inthe valve guide 360 to serve as a guide hole. A portion of the valveguide 360, approaching the power-receiving portion 521 c at least whenthe valve head 522 closes the combustion chamber side opening of theexhaust port 320, is the dielectric member. This makes it possible tohave non-contact electromagnetic wave transmission from electromagneticwave generator 840 to electromagnetic wave transmission line 830 byusing heretofore known mechanism for mounting the valve guide.

The positional relationship between the antenna and the electrode is notrestricted for the plasma apparatus using a valve of the presentinvention. In the first embodiment of the plasma apparatus using avalve, first electrode 812 and second electrode 813 are located close toa portion where the electric field intensity generated by theelectromagnetic waves around the valve face 522 b of the valve head 522becomes strong when the electromagnetic waves are fed to the antenna820. This makes it possible that the electromagnetic wave pulseirradiates the plasma generated by the discharge at first electrode 812and second electrode 813 from the antenna near plasma. The energy isintensively supplied to said plasma. As a result, a large amount of OHradicals and ozone is efficiently generated, further promoting thecombustion.

Next, the second embodiment of the plasma apparatus using a valve of thepresent invention will be described. This plasma apparatus using a valvediffers from the first embodiment only in the composition of exhaustvalve 520. In the exhaust valve 520 of the plasma apparatus in the firstembodiment, the interior of valve stem 521 that fits into guide hole 340is made from a dielectric or insulator as a basic portion 521 a.Moreover, a fitting portion into the guide hole 340 on the periphery ofthe basic portion 521 a is made from metal as a periphery portion 521 b.In the exhaust valve 520 of the plasma apparatus in the secondembodiment, not only basic portion 521 a but periphery portion 521 b arean integral structure and are made from a dielectric or insulator, asshown in FIG. 5. This increases the relative volume of the dielectric orinsulator for the same valve stem 521 diameter. Thus, if the impedanceof electromagnetic wave transmission line 830 is same level between thefirst and second embodiments, the cross-sectional area ofelectromagnetic wave transmission line 830 for the second embodimentwill be larger, increasing the transmitting efficiency. Other functionsand effects are similar to the first embodiment of the plasma apparatus.

In the plasma apparatus using a valve of the present invention, a pairof the electrodes or a pair of the electrode and the earth member may aswell be covered with a dielectric. In this case, the dielectric-barrierdischarge is generated by voltage applied between the electrodes orbetween the electrode and the earth member. The dielectric-barrierdischarge is restricted because charges are accumulated in the surfaceof the dielectric covering the electrode or the earth member. Therefore,the discharge is generated on a very small scale over a very shortperiod of time. Thermalization does not occur in the area surroundingthe discharge because the discharge is terminated after a short periodof time. Therefore, the gas temperature rise due to the dischargebetween the electrodes is reduced, which reduces the amount of NOxproduced by the internal combustion engine.

In the embodiment mentioned above, the plasma apparatus is composed byusing the exhaust valve. That is, these plasma apparatus has the antenna820 arranged on the valve face 522 b of the valve head 522 of theexhaust valve 520. The electromagnetic wave transmission line 830 isinstalled in the valve stem 521 of the exhaust valve 520. Theelectromagnetic wave generator 840 for feeding electromagnetic waves isin the power-receiving portion 521 c which is arranged on the valve stem521 of the exhaust valve 520. At compression stroke when the valve head522 of the exhaust valve 520 closes the combustion chamber side opening321 of the exhaust port 320, this plasma apparatus configures thatdischarge is generated between the electrodes of the discharge device810, and electromagnetic waves fed from the electromagnetic wavegenerator 840 through the electromagnetic wave transmission line 830 isradiated from the antenna 820. But the present invention includes anembodiment which the plasma apparatus is composed by using an intakevalve. That is, the plasma apparatus using an intake valve has anantenna arranged on the valve face of the valve head of the intakevalve. An electromagnetic wave transmission line is installed in thevalve stem of the intake valve. The electromagnetic wave generator forfeeding electromagnetic waves is installed in the power-receivingportion which is arranged on the valve stem of the intake valve. At thecompression stroke when the valve head of the intake valve closes thecombustion chamber side opening of said intake port, this plasmaapparatus configures that discharge is generated between the electrodesof the discharge device 810, and electromagnetic waves fed from theelectromagnetic wave generator through the electromagnetic wavetransmission line 830 is radiated from the antenna 820. In this case,the component of the intake valve, the antenna, the electromagnetic waveline, the power-receiving portion, the electromagnetic wave generator,the discharge device, and the electrodes of the discharge device issimilar to the exhaust valve etc. of the plasma apparatus using theexhaust valve. Functions and effects of the plasma apparatus using theintake valve are similar to the case of said each embodiment. Theantenna forms nearly a C-shaped to surround the center of the valveface. Functions and effects, in the case that one end of this antenna isconnected to electromagnetic wave transmission line, are similar to thecase of said each embodiment. The power-receiving portion is exposed onouter surface of said valve stem. The dielectric member is installed insaid cylinder head, and gets close to said power-receiving portion, atleast when said valve head closes the combustion chamber side opening ofthe intake port. The dielectric member is made from dielectric. Thepower-feeding member is installed in the cylinder head. Thepower-feeding member, made from conductive, gets close to the dielectricmember from the opposite side of the valve stem. Functions and effectsare similar to the case of said each embodiment in the case thatelectromagnetic waves are supplied from the electromagnetic wavegenerator to the power-receiving portion. In addition, a valve guidemounted hole, which penetrates from the intake port to the outer wall ofthe cylinder head, in installed in the cylinder head. The valve guidewith trunk shape made from a ceramics fits into the valve guide mountedhole, allowing a hole in the valve guide 360 to serve as a guide hole340. Functions and effects are similar to the case of said eachembodiment in the case that a portion of the valve guide, approachingsaid power-receiving portion at least when said valve head closes thecombustion chamber side opening of the intake port, is the dielectricmember. Moreover, Functions and effects are similar to the case of saideach embodiment in the case that the electrodes are located close to aportion that electric field intensity, generated by the electromagneticwaves in the antenna, becomes strong when the electromagnetic waves arefed to said antenna.

The present invention includes some embodiments that combine thecharacteristics of the embodiments described above. Moreover, theembodiments described above are only examples of the plasma apparatususing a valve of the present invention. Thus, the description of theseembodiments does not restrict interpretation of the plasma apparatususing a valve of the present invention.

1. A plasma apparatus using a valve, which is installed in an internalcombustion engine in which the combustion chamber side opening of anintake port or an exhaust port is opened and closed at a given timingwith a valve head at the end of a valve stem of an intake valve or anexhaust valve, the intake port is formed in a cylinder head and connectsto the combustion chamber to be part of an intake passage, the exhaustport is formed in the cylinder head and connects to the combustionchamber to be part of an exhaust passage, the valve stem fits into aguide hole penetrating from the intake port or the exhaust port to theouter wall of the cylinder head and reciprocating freely, the plasmaapparatus comprising: a discharge device with an electrode exposed tothe combustion chamber installed in the cylinder head; an antennainstalled on the valve face of the valve head; an electromagnetic wavetransmission line installed in the valve stem with one end connected tothe antenna and the other end, covered with an insulator or dielectricand extending to a power-receiving portion, which is positioned at alocation fitting into the guide hole or at a location farther from thevalve head in the valve stem; and an electromagnetic wave generator forfeeding electromagnetic waves to the power-receiving portion; whereinthe plasma apparatus is configured such that discharge is generated withthe electrode of the discharge device and the electromagnetic waves fedfrom the electromagnetic wave generator through the electromagnetic wavetransmission line are radiated from the antenna at the compressionstroke when the combustion chamber side opening of the intake port orthe exhaust port is closed with the valve head.
 2. The plasma apparatusaccording to claim 1, wherein the antenna forms nearly a C shape tosurround the center of the valve face and one end of the antenna isconnected to the electromagnetic wave transmission line.
 3. The plasmaapparatus according to claim 1, wherein the power-receiving portionexposed on the outer wall of valve stem, and the plasma apparatusincludes: a dielectric member installed in the cylinder head and nearthe power-receiving portion, at least when the valve head closes thecombustion chamber side opening of the intake port or the exhaust port,made from dielectric material; and a power-feeding member made fromconductive material, which is installed in the cylinder head close tothe dielectric member opposite the valve stem; wherein plasma apparatusis configured such that the power-feeding member would be fed theelectromagnetic waves from the electromagnetic wave generator.
 4. Theplasma apparatus according to claim 1, wherein a valve guide mountedhole, which penetrates from the intake port or the exhaust port to theouter wall of cylinder head, is installed in the cylinder head, a valveguide with trunk shape made from dielectric material fits into the valveguide mounted hole allowing a hole in the valve guide to serve as aguide hole, and a portion of the valve guide, approaching thepower-receiving portion at least when the valve head closes thecombustion chamber side opening of the intake port or the exhaust port,is the dielectric member.
 5. The plasma apparatus according to claim 1,wherein the electrode is located close to a portion where the electricfield intensity generated by the electromagnetic waves around the valveface of the valve head becomes strong when the electromagnetic waves arefed to the antenna.
 6. The plasma apparatus according to claim 2,wherein the power-receiving portion exposed on the outer wall of valvestem, and the plasma apparatus includes: a dielectric member installedin the cylinder head and near the power-receiving portion, at least whenthe valve head closes the combustion chamber side opening of the intakeport or the exhaust port, made from dielectric material; and apower-feeding member made from conductive material, which is installedin the cylinder head close to the dielectric member opposite the valvestem; wherein plasma apparatus is configured such that the power-feedingmember would be fed the electromagnetic waves from the electromagneticwave generator.
 7. The plasma apparatus according to claim 2, wherein avalve guide mounted hole, which penetrates from the intake port or theexhaust port to the outer wall of cylinder head, is installed in thecylinder head, a valve guide with trunk shape made from dielectricmaterial fits into the valve guide mounted hole allowing a hole in thevalve guide to serve as a guide hole, and a portion of the valve guide,approaching the power-receiving portion at least when the valve headcloses the combustion chamber side opening of the intake port or theexhaust port, is the dielectric member.
 8. The plasma apparatusaccording to claim 3, wherein a valve guide mounted hole, whichpenetrates from the intake port or the exhaust port to the outer wall ofcylinder head, is installed in the cylinder head, a valve guide withtrunk shape made from dielectric material fits into the valve guidemounted hole allowing a hole in the valve guide to serve as a guidehole, and a portion of the valve guide, approaching the power-receivingportion at least when the valve head closes the combustion chamber sideopening of the intake port or the exhaust port, is the dielectricmember.
 9. The plasma apparatus according to claim 2, wherein theelectrode is located close to a portion where the electric fieldintensity generated by the electromagnetic waves around the valve faceof the valve head becomes strong when the electromagnetic waves are fedto the antenna.
 10. The plasma apparatus according to claim 3, whereinthe electrode is located close to a portion where the electric fieldintensity generated by the electromagnetic waves around the valve faceof the valve head becomes strong when the electromagnetic waves are fedto the antenna.
 11. The plasma apparatus according to claim 4, whereinthe electrode is located close to a portion where the electric fieldintensity generated by the electromagnetic waves around the valve faceof the valve head becomes strong when the electromagnetic waves are fedto the antenna.